1. Technical Field
The present invention relates generally to an apparatus and method for acquiring three-dimensional (3D) depth information and, more particularly, to an apparatus and method for acquiring 3D depth information using an image in order to detect the movement of a user who is moving across a space.
2. Description of the Related Art
Optical methods are a widely used method for acquiring a depth image representative of a distance in a space.
An optical method includes a passive acquisition method using a plurality of cameras to provide two or more points of view and an active acquisition method of projecting light into a space and analyzing the projected light.
The passive acquisition method is widely known as stereo vision, and is a method in which two cameras are used just as human vision uses both eyes or is a method in which a three or more viewpoint camera system is used.
The passive acquisition method is disadvantageous in that it is difficult to measure the distance when it is difficult to find a feature point where a change in brightness value is present in a space where the distance is desired to be measured.
The active acquisition method is advantageous in that it is not significantly influenced by the illumination of a space or the presence or absence of a feature point and in that it is possible to accurately measure distances.
However, the active acquisition method generally uses visible light, in which case it is difficult to apply the active acquisition method to the case where a human is present due to a dazzling phenomenon. Furthermore, the active acquisition method is disadvantageous in that it is difficult to apply the active acquisition method to a situation where there is motion because a plurality of patterns is projected.